Video API Extensions legacy

in English | [[{{{de}}}|deutsch]] | [[{{{fr}}}|français]] | по-русски | автоперевод | 中文版 | 机械翻译

The current implementation of the Video API has a number of features which are absent from the standard Axis Video API.

Enabling extensions

By default the Video API extensions are blocked. To unblock them it is necessary to set a corresponding variable:

http://192.168.0.9/axis-cgi/admin/param.cgi?action=update&ElphelExtensions.Enabled=yes

Obtaining static and dynamic images

The standard interface for obtaining static and dynamic images in JPEG and MJPG formats has a few additional parameters.

e_dcm_hor	-	horizontal decimation (resolution/image size reduction)
e_dcm_vert	-	vertical decimation (resolution/image size reduction)
e_bin_hor	-	horizontal binning (sensitivity for lower resolution)
e_bin_vert	-	vertical binning (sensitivity for lower resolution)
e_woi_width	-	sensor active window width (before decimation)
e_woi_height	-	sensor active window height (before decimation)
e_woi_left	-	sensor active window left margin (before decimation)
e_woi_top	-	sensor active window top margin (before decimation)
e_virt_width	-	virtual frame width
e_virt_height	-	virtual frame height
e_fliph	-	flip (mirror) image horizontally (uses in-sensor capabilities)
e_flipv	-	flip (mirror) image vertically (uses in-sensor capabilities)
e_quality	-	JPEG Quality (%)

Examples

Example of obtaining a static image - use the following parameters:

http://192.168.0.9/axis-cgi/jpg/image.cgi?e_dcm_hor=2&e_dcm_vert=2&e_woi_width=1000&e_woi_height=900&e_woi_left=600

Example of obtaining a dynamic image (MPJPG) - use the following parameters:

http://192.168.0.9/axis-cgi/mjpg/video.cgi?e_dcm_hor=2&e_dcm_vert=2&e_woi_width=1000&e_woi_height=900&e_woi_left=600

You can play this videostream, for example, by using MPlayer (for a more detailed description see Using Mplayer With Video API):

$mplayer -demuxer lavf "http://192.168.0.9/axis-cgi/mjpg/video.cgi?e_dcm_hor=2&e_dcm_vert=2&e_woi_width=1000&e_woi_height=900&e_woi_left=600&bogus.mjpg"

If any of the parameters are not specified, the default values are used. You can find these values at the address:

http://192.168.0.9/axis-cgi/admin/param.cgi?action=list&group=ImageSource.I0.Sensor

Note: All API extensions have the prefix "E_".

You can change the default value in the standard way for the Axis Video API. For example:

http://192.168.0.9/axis-cgi/admin/param.cgi?action=update&ImageSource.I0.Sensor.E_DcmHor=1

Obtaining information about the system status and default values

To obtain information about the system status variable you must use the following path:

http://192.168.0.9/axis-cgi/admin/param.cgi?action=list&group=ImageSource.I0.E_CurrentState

In an addition to the standard "rfc" format there is also the possibility to use XML format. You must use the responseformat parameter for this. For example:

http://192.168.0.9/axis-cgi/admin/param.cgi?action=list&group=ImageSource.I0.E_CurrentState&responseformat=xml

Note. If the responseformat is not specified or specified incorrectly, the default value of "rfc" will be used.

Video streaming: RTP/MJPG and RTP/Theora

The Elphel cameras can transfer the video stream by RTP protocol.

RTP/MJPG

RTP/Theora

Exposure control

The Elphel cameras support the standard and advanced exposure control interface. For the standard settings see Video_API

To enable autoexposure it is necessary to use the following command:

http://192.168.0.9/axis-cgi/admin/param.cgi?action=update&ImageSource.I0.Sensor.Exposure=auto

Enabling the manual control of exposure:

http://192.168.0.9/axis-cgi/admin/param.cgi?action=update&ImageSource.I0.Sensor.Exposure=manual

Obtaining the exposure state:

http://192.168.0.9/axis-cgi/admin/param.cgi?action=list&group=ImageSource.I0.E_CurrentState.E_Exposure

Window settings:

http://192.168.0.9/axis-cgi/admin/param.cgi?action=update&ImageSource.I0.Sensor.E_Exposure.E_WinWidth=30&ImageSource.I0.Sensor.E_Exposure.E_WinHeight=45&ImageSource.I0.Sensor.E_Exposure.E_WinLeft=10&ImageSource.I0.Sensor.E_Exposure.E_WinTop=20

Exposure max.values:

http://192.168.0.9/axis-cgi/admin/param.cgi?action=update&ImageSource.I0.Sensor.E_Exposure.E_Max=3000&ImageSource.I0.Sensor.E_Exposure.E_OverMax=30